linux/arch/arm/mach-pnx4008/sleep.S

/*
 * linux/arch/arm/mach-pnx4008/sleep.S
 *
 * PNX4008 support for STOP mode and SDRAM self-refresh
 *
 * Authors: Dmitry Chigirev, Vitaly Wool <source@mvista.com>
 *
 * 2005 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */

#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/hardware.h>

#define PWRMAN_VA_BASE IO_ADDRESS(PNX4008_PWRMAN_BASE)
#define PWR_CTRL_REG_OFFS 0x44

#define SDRAM_CFG_VA_BASE IO_ADDRESS(PNX4008_SDRAM_CFG_BASE)
#define MPMC_STATUS_REG_OFFS 0x4

		.text

ENTRY(pnx4008_cpu_suspend)
	@this function should be entered in Direct run mode.

	@ save registers on stack
	stmfd	sp!, {r0 - r6, lr}

	@ setup Power Manager base address in r4
	@ and put it's value in r5
	mov	r4, #(PWRMAN_VA_BASE & 0xff000000)
	orr	r4, r4, #(PWRMAN_VA_BASE & 0x00ff0000)
	orr	r4, r4, #(PWRMAN_VA_BASE & 0x0000ff00)
	orr	r4, r4, #(PWRMAN_VA_BASE & 0x000000ff)
	ldr	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ setup SDRAM controller base address in r2
	@ and put it's value in r3
	mov	r2, #(SDRAM_CFG_VA_BASE & 0xff000000)
	orr	r2, r2, #(SDRAM_CFG_VA_BASE & 0x00ff0000)
	orr	r2, r2, #(SDRAM_CFG_VA_BASE & 0x0000ff00)
	orr	r2, r2, #(SDRAM_CFG_VA_BASE & 0x000000ff)
	ldr	r3, [r2, #MPMC_STATUS_REG_OFFS] @extra read - HW bug workaround

	@ clear SDRAM self-refresh bit latch
	and	r5, r5, #(~(1 << 8))
	@ clear SDRAM self-refresh bit
	and	r5, r5, #(~(1 << 9))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ do save current bit settings in r1
	mov	r1, r5

	@ set SDRAM self-refresh bit
	orr	r5, r5, #(1 << 9)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ set SDRAM self-refresh bit latch
	orr	r5, r5, #(1 << 8)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ clear SDRAM self-refresh bit latch
	and	r5, r5, #(~(1 << 8))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ clear SDRAM self-refresh bit
	and	r5, r5, #(~(1 << 9))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ wait for SDRAM to get into self-refresh mode
2:	ldr	r3, [r2, #MPMC_STATUS_REG_OFFS]
	tst	r3, #(1 << 2)
	beq	2b

	@ to prepare SDRAM to get out of self-refresh mode after wakeup
	orr	r5, r5, #(1 << 7)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ do enter stop mode
	orr	r5, r5, #(1 << 0)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop
	nop

	@ sleeping now...

	@ coming out of STOP mode into Direct Run mode
	@ clear STOP mode and SDRAM self-refresh bits
	str	r1, [r4, #PWR_CTRL_REG_OFFS]

	@ wait for SDRAM to get out self-refresh mode
3:	ldr	r3, [r2, #MPMC_STATUS_REG_OFFS]
	tst	r3, #5
	bne	3b

	@ restore regs and return
	ldmfd   sp!, {r0 - r6, pc}

ENTRY(pnx4008_cpu_suspend_sz)
	.word	. - pnx4008_cpu_suspend

ENTRY(pnx4008_cpu_standby)
	@ save registers on stack
	stmfd	sp!, {r0 - r6, lr}

	@ setup Power Manager base address in r4
	@ and put it's value in r5
	mov	r4, #(PWRMAN_VA_BASE & 0xff000000)
	orr	r4, r4, #(PWRMAN_VA_BASE & 0x00ff0000)
	orr	r4, r4, #(PWRMAN_VA_BASE & 0x0000ff00)
	orr	r4, r4, #(PWRMAN_VA_BASE & 0x000000ff)
	ldr	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ setup SDRAM controller base address in r2
	@ and put it's value in r3
	mov	r2, #(SDRAM_CFG_VA_BASE & 0xff000000)
	orr	r2, r2, #(SDRAM_CFG_VA_BASE & 0x00ff0000)
	orr	r2, r2, #(SDRAM_CFG_VA_BASE & 0x0000ff00)
	orr	r2, r2, #(SDRAM_CFG_VA_BASE & 0x000000ff)
	ldr	r3, [r2, #MPMC_STATUS_REG_OFFS] @extra read - HW bug workaround

	@ clear SDRAM self-refresh bit latch
	and	r5, r5, #(~(1 << 8))
	@ clear SDRAM self-refresh bit
	and	r5, r5, #(~(1 << 9))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ do save current bit settings in r1
	mov	r1, r5

	@ set SDRAM self-refresh bit
	orr	r5, r5, #(1 << 9)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ set SDRAM self-refresh bit latch
	orr	r5, r5, #(1 << 8)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ clear SDRAM self-refresh bit latch
	and	r5, r5, #(~(1 << 8))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ clear SDRAM self-refresh bit
	and	r5, r5, #(~(1 << 9))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ wait for SDRAM to get into self-refresh mode
2:	ldr	r3, [r2, #MPMC_STATUS_REG_OFFS]
	tst	r3, #(1 << 2)
	beq	2b

	@ set 'get out of self-refresh mode after wakeup' bit
	orr	r5, r5, #(1 << 7)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	mcr     p15, 0, r0, c7, c0, 4	@ kinda sleeping now...

	@ set SDRAM self-refresh bit latch
	orr	r5, r5, #(1 << 8)
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ clear SDRAM self-refresh bit latch
	and	r5, r5, #(~(1 << 8))
	str	r5, [r4, #PWR_CTRL_REG_OFFS]

	@ wait for SDRAM to get out self-refresh mode
3:	ldr	r3, [r2, #MPMC_STATUS_REG_OFFS]
	tst	r3, #5
	bne	3b

	@ restore regs and return
	ldmfd   sp!, {r0 - r6, pc}

ENTRY(pnx4008_cpu_standby_sz)
	.word	. - pnx4008_cpu_standby

ENTRY(pnx4008_cache_clean_invalidate)
	stmfd	sp!, {r0 - r6, lr}
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
	mcr	p15, 0, ip, c7, c6, 0		@ invalidate D cache
#else
1:	mrc	p15, 0, r15, c7, c14, 3		@ test,clean,invalidate
	bne     1b
#endif
	ldmfd   sp!, {r0 - r6, pc}